I've ended up with:
linux-p9bp:/home/laura # du -sh /var/cache/zypp/packages/*
8.0K /var/cache/zypp/packages/libdvdcss repository
1.1G /var/cache/zypp/packages/Packman Repository
So it looks like it, yes. Odd, I didn't think I had very much installed. I'll have a dig through and see what I can get rid of. I still don't understand why the other updates went through too when they were larger.